quickly reach living facilities near their residences
became mainstream during the epidemic. This also
re-exposed the concept of the 15-minute city (Van
Der Waals, 2000). Today, more and more cities are
beginning to embark on the path of practicing the
15mc concept. The first to start was Paris, France,
which launched the world's first shared bicycle
system as early as 2001. American urban planning is
also abandoning the previous development model of
car-first and returning to the city concept of people-
oriented. There is a common topic in China: the 15-
minute convenient living circle, which is the Chinese
community development concept before 15mc was
formally proposed. Now, after integrating with the
15mc theory, it has also begun to be systematically
implemented in major cities in China. For example,
Shanghai, Shenzhen, Lanzhou and other cities have
successively launched their own 15-minute living
circle experimental communities (Wu, 2021).
The 15-minute city is a conceptualization of the
principles of accessibility and sustainable
development through the 15-minute city approach, in
which the four principles of proximity, diversity,
digitization, and reasonable building density should
be followed in conjunction with the development of
the new digital age (Cui, 2023). Proximity refers to
the short spatial distance between places at the
architectural level, which is measured in terms of the
travel time of residents, meaning that pedestrians can
reach the public facilities or places they need in their
lives within 15 minutes by walking or cycling. This is
a core and one of the objectives of the 15-minute city
concept. In realizing the 15-minute city concept, the
need to select appropriately scoped and well-laid-out
neighborhoods are the foundation of the concept.
Overemphasis on density is not a permanent solution;
even if the density is too high for residents to reach at
a certain time, it is still empty talk. Therefore, rational
transportation and urban layout that enables travellers
to reach their destinations within 15 minutes is the
core. Diversity refers to both spatial and temporal
diversity (Manakina, 2020). Spatially, residents can
reach different functional facilities and places within
15 minutes, and this diversity meets the differentiated
needs of citizens, making community life more
convenient and community ties closer. The
differentiation of workplaces is also a form of spatial
diversity, especially the online office that became
popular during the epidemic is one of the most
important ways to realize the 15-minute city because
most of the necessary commuting is for work
purposes. Home-based or free-space offices can
effectively reduce long-distance commuting while
reducing the various costs and environmental
pollution generated by transportation. Spatial
diversity also includes a variety of transportation
options: within a 15-minute neighbourhood, residents
can choose to walk, bike, etc.; within a larger 30-
minute or even 45-minute living area, they can choose
to use public transportation such as buses, subways,
and other modes of transportation.
Diversity in time can be understood as the same
building or site serving different purposes under
different time conditions. For example, the school
playground can be used as a place for student
activities and teaching during the school year.
However, during vacation time, most students and
teachers are not in the school for teaching activities,
so the schoolyard can be used as a venue for large-
scale activities or as a parking lot, which greatly
increases the usability of buildings with tidal
properties. A deeper practice of temporal diversity for
urban participants is the variability of working hours.
Unlike workplace diversity, time diversity means that
people with different jobs travel to their workplaces
at different times, a policy that is being implemented
in many major cities such as Beijing and Los Angeles.
This measure allows the transportation system to
avoid peak traffic and increase operational efficiency,
resulting in shorter commute times and reduced urban
loads.
In the process of practicing the 15-minute city,
digitalization and intelligent technology have also
gradually become indispensable components.
Combined with the traffic control realized by
intelligent technology, digitalization can improve the
efficiency and accuracy of urban management.
Strengthening the construction of the information city
and promoting the improvement of information
technology infrastructure can significantly improve
the accessibility of the city, and effectively improve
the city's existing problems and pitfalls, such as traffic
congestion, carbon emissions, and so on. Although
the 15-minute city theory does not overly emphasize
the concept of digitization, incorporating
digitalization into the 15-minute city concept is
certainly a more efficient and accurate way of
practising it in this day and age.
As mentioned earlier, the pursuit of density in
building layouts is not the best solution. Many large
cities in developing countries, such as New Delhi in
India and Cairo in Egypt, have large populations of
more than 20 million people. However, due to uneven
economic development and poor urban layout, the
distribution of urban infrastructure is extremely
uneven, resulting in significant differences between
communities. This has led to increased fragmentation
and uneven distribution of resources within cities,